We investigated the phylogenetic position the Ohiya rat (Srilankamys ohiensis), endemic to Sri Lanka, Srilankamys (Rodentia), within the tribe Rattini based on the combined analysis of three independent genes (a mitochondrial one and two nuclear exons). Three major lineages (the Maxomys, the Dacnomys and the Rattus divisions) were retrieved as monophyletic groups within the tribe Rattini. Srilankamys was not affiliated to any of the representatives of the Dacnomys division as it was supposed based on morphological characters, but clearly appeared as the first genus to diverge among the Rattus division. Molecular date of divergence between Srilankamys and the other representatives of the Rattus division falls within the interval 6.7 ± 0.74 Mya, coinciding with the time of the isolation of Sri Lanka from the Deccan peninsula and the aridification period owing to the climate change at the end of the Miocene epoch. We suggest that the isolation of Sri Lanka from the continent, reinforced by the action of a seasonal monsoon-dominated climate, would have led to the isolation of some ancestral rodents of the Rattus division, which would have differentiated later into the Ohiya rat by a vicariant process. In a more general point of view, Sri Lanka appears to be characterized by a particular fauna as compared to the Indian mainland. This island would therefore be considered as a specific distinct hotspot of biodiversity.
COBISS.SI-ID: 2081491
Analysis of a sequence for the mitochondrial cytochrome b gene rejected the hypothesis of the Balkan peninsula as a refugium for the Eastern phylogeographic lineage of the common vole Microtus arvalis. In the southern Balkans the species evolved an endemic lineage, which is not in a sister position against the Eastern lineage. The study offers a new insight into the evolution of the model species, and on the legacy of glacial refugia for current biodiversity.
COBISS.SI-ID: 1832403
The spatial genetic structure of Martino’s vole, a rare palaeoendemic species of the western Balkans, was investigated using DNA isolated from archived museum samples. The nuclear markers confirmed existences of three highly divergent allopatric phylogenetic lineages (Northwestern, Central and Southeastern), which were recognized among 47 haplotypes, suggesting three independent glacial differentiation centres within the western Balkans. The three main lineages should be regarded as evolutionary significant units with important implications for conservation.
COBISS.SI-ID: 1791955
Mole rats (genus Nannospalax) display prolific chromosomal variation with more than 50 distinct cytotypes. These cytotypes are largely indistinguishable morphologically, are mainly allopatric and their taxonomic ranking is contradictory. We established a cytochrome b phylogeny for 15 cytotypes belonging to all three species recognized on morphological grounds (morphospecies): N. leucodon, N. xanthodon and N. ehrenbergi. Phylogenetic reconstructions yielded two highly divergent groups which are in agreement with the current division into two subgenera (Nannospalax and Mesospalax). The former comprised samples from south-eastern Turkey, Israel and Egypt (the morphospecies N. ehrenbergi). Basal dichotomy within Mesospalax remained unresolved and the putative sister position of N. leucodon against the two lineages of N. xanthodon was not supported in our analysis. Net divergences between sister cytotypes were low (( 2.0%) and two N. leucodon cytotypes were not even reciprocally monophyletic. Among the three morphospecies, the genetic diversity was lowest in N. leucodon (2.4% ± 0.3%), highest in N. xanthodon (8.8% ± 0.7%) and intermediate in N. ehrenbergi (5.0% ± 0.5%). Our results show that associations between genetic and chromosomal variation are not widespread and common in mole rats, and therefore refute the generalization of a ‘cytotype-equals-species’ approach.
COBISS.SI-ID: 2117075
Using molecular markers (complete cytochrome b gene sequence) we reconstructed phylogenetic history of social voles in the Balkans and SW Asia. We recognized 6 monophyletic lineages which we interprete as distinct species. These species cluster into two evolutionary lineages (the socialis and the guentheri linegae). Within its present scope, M. guentheri is paraphyletic with respect to M. hartingi. Microtus hartingi most probably evolved in W Anatolia and colonized Europe relatively late.
COBISS.SI-ID: 1653459